The objectives of this project are to investigate the differences among individuals in the induction of the microsomal enzyme system, aryl hydrocarbon hydroxylase (AHH). Previous studies have demonstrated that this enzyme system is induced to high levels in the pulmonary macrophages of normal healthy individuals who regularly inhale cigarette smoke. A number of polycyclic hydrocarbons are capable of inducing AHH in vitro. This study is designed to study the in vivo induction of AHH in pulmonary cells obtained from patients with inflammatory lung diseases, pulmonary tuberculosis, and lung cancer. During the current year, we will continue to study enzyme levels in cells obtained from patients undergoing diagnostic bronchoscopy for a variety of medical indications. We will compare the ability of lymphocytes from the peripheral blood of patients to be induced in vitro for AHH with the degree of induction which has occurred in the lung cells of cigarette smokers and non-smokers. In addition, Dr. Cantrell's component of this project (laboratories at North Texas State University in Denton, Texas) will continue to work on improved methods of assay for the pulmonary cells and for the induced enzyme in peripheral blood lymphocytes. Where possible, assays of other tissues, such as organ cultures of skin fibroblasts and specimens from surgically resected lungs, will be assayed for AHH activity or inducibility.